REMOVE

1. boys
2. utility poles
3. trees
4. soil
5. rubbish

WHAT

1. Visual Works (hierarchy n … (1)
2. cliffs (1)
3. coastlines (1)
4. exterior views (1)
5. houses (1)

More 

WHERE

1. California (1)

WHO

1. Clyfford Still; Still, Cl … (1)
2. Still, Clyfford (1)

WHEN

1. 1920 (1)
2. 1945 (1)
3. between circa 1929 and ci … (1)